That's a tough one to be honest, but this is ons that came up in my head at the moment: (more later)
* I Have No Mouth, and I Must Scream (PC) - Ok, even though I liked the story of this game I must give a warning that it's NOT for everyone, especially since this is a old point-and-click adventure game (not going to judge you if you end up using a guilde, I did that to for some parts at least), and it touches unconfortable themes.
It's based around the short story of the same name by Harlan Ellison, and he even had some involvement in the production of this game. It's about a "what if" scenario where after the Cold War things excalated to World War III, and AM (short for Allied Mastercomputer) was a supercomputer that was created to manage logistics and the war in general, but he got self-aware (and deciding to adopt the name AM as now a reference to the quote "I think, therefore I am" by Descartes) and decided to destroy humanity, with the exception of five humans (which are either bad people or have psycological problems, or both) which he even granted immortality so he could torture them for eternity to exercise is endless hatred on humans.
The game centers around you playing as these five characters, one at a time, to experience AM next sadistic game. Beyond some of the puzzles, I think the voice acting aged quite poorly in some parts, with the exception of AM, that's voiced by Harlan Ellison himself, and he does a really great job.
Sidenote: If anyone here saw the Amazing Digital Circus show on Youtube, "I Have No Mouth, and I Must Scream" is one of it's biggest inspirations.